Friday, March 11, 2016

Friday Science: Greene's Roads to Reality (1)

Physics is moving fast. The Higgs boson, gravitational waves, it seems we're on the verge of something big. This week I started reading through Brian Greene's, The Fabric of the Cosmos, which gives a fair sense of where things were in 2004. [BTW, I've collected a number of my science book reviews here.]

1. He starts interestingly by disagreeing with Albert Camus in the Myth of Sisyphus. Sorry Brian, having a reason to live is still more existentially important than knowing the secrets of the universe. The laws of the universe won't change whether I know them or not. But if I don't have a reason to live, the secrets of the universe are irrelevant to me.

2. Greene briefly covers the old stomping grounds of all books like this one. The next few pages are a map to the rest of the book, a brief preview.

He starts with Newton and "classic reality." For Newton, the laws of nature were deterministic. If we knew all the variables and all the laws, we could predict everything that would happen for the rest of time. Second, time and space were absolute scaffolds that provided the universe with a rigid, unchangeable area.

3. So next he mentions relativity. Einstein showed that space and time can expand and collapse both as something approaches the speed of light and as one approaches something of great mass.

4. Next comes the quantum changes. Newton was wrong about determinism. We cannot predict what will happen, only the odds. Strangely, there can be an instantaneous connection between things that happen at completely different locations.

5. It is clear that cosmology has been the next phase. Weinberg and Hawking are the big names here. Why is it that time only moves in one direction when nothing in the laws of physics would prohibit a backwards movement. It may have something to do with something that happened in the very earliest moments of the universe.

6. As he moves toward the end of the chapter, he begins to talk about the quest for a unified reality. Quantum mechanics and relativity are currently incompatible, and physics will not be able to move much further until that conflict is solved. Greene clearly is sympathetic with string theory as a possible way to harmonize them.